Singlephase εFe3N magnetic fluid with saturation magnetization 1633Gs was successfully prepared by homemade equipment. TEM measurement shows that the dispersion of the magnetic particle in the carrier is quite homogeneous and the average size of the particle is 15-20 nm. The εFe3N magnetic fluid with the saturation magnetization more than 1 000 Gs can be obtained in a shorter time by adding the concentration reagent NS to the carrier during preparation.